WASHINGTON -- Senate Majority Leader Trent Lott urged Democrats yesterday to "calm down" and not rush forward with a censure deal for President Clinton, saying the Senate must hear a full presentation of the evidence before deciding his fate.

"We need to go forward and do our constitutional duty to hear the evidence," Lott, a Mississippi Republican, said in an interview.

He also warned that a censure resolution that commands bipartisan support could be trickier to negotiate and craft than some assume.

"I don't think a magic formula has been found yet" to put an end to the impeachment controversy, Lott added.

And laying down a partisan gantlet, he disparaged Senate Democrats, most of whom are said to oppose convicting Clinton on charges of perjury and obstruction of justice in handling disclosures that he had an adulterous affair with Monica S. Lewinsky.

"Are they all loony left?" Lott asked. "Are there no Democrats that are offended if, in fact, the evidence proves perjury or obstruction of justice? Surely there are some Democrats that will be concerned about that."

Lott's go-slow remarks should reassure hard-line conservatives who fear that a handful of GOP moderates might join the Senate's 45 Democrats in fashioning what amounts to a plea bargain for Clinton without the benefit of a full trial -- and votes on the two articles of impeachment.

Since the House voted Dec. 19 to impeach, largely along party lines, a groundswell has developed for censuring Clinton as a way to abort a full-blown Senate trial.

But in an afternoon telephone interview from his Pascagoula, Miss., office, Lott insisted that such a proceeding -- due to begin late next week -- must go forward.

At the very least, he said, Rep. Henry J. Hyde should present the case against Clinton before the full Senate. As chairman of the House Judiciary Committee, Hyde, an Illinois Republican, also will serve as the chief prosecutor, or "manager," during the trial.

Only after Hyde's presentation, and a response from the White House, Lott said, could there be votes on the two articles of impeachment or some other form of punishment, such as censure.

Hyde has previously said he does not intend to call any witnesses and instead would rely on the evidence developed by independent counsel Kenneth W. Starr, which formed the basis of the articles of impeachment.

But that could change. Hyde and his 12 "managers" are to meet today behind closed doors to map out further strategy and assign areas of responsibilities.

"I think that you will see different options discussed for the presentation of evidence," said a House Judiciary Committee aide.